6.6.3. Example of Signal Handling

Try these first

1. 1.

   What is a signal in the context of Linux?

   Hint

   Think about how a computer alerts a program.

2. 2.

   What does the SIGINT signal typically indicate?

   Hint

   Consider user actions that stop running programs.

3. 3.

   What is the purpose of the signal() function?

   • To send signals between applications
   • To register a signal handler
   • To handle system calls

   Hint

   Think about how we inform the program about what to do when a signal arises.

4. 4.

   True or False: A signal handler can be defined using the sigaction() function.

   • True
   • False

   Hint

   Consider both functions that relate to signals.

5. 5.

   Design a simple C program that registers a signal handler for SIGTERM. The program should perform a cleanup operation (e.g., closing files) and then terminate gracefully when SIGTERM is received.

   Hint

   Think about what resources need to be cleaned before exiting.

6. 6.

   Explain how user-defined signal handlers can create race conditions in concurrent applications. Provide an example where this might occur.

   Hint

   Consider situations where multiple threads may be waiting on signals or shared locks.